Why we need Jackson api for JSON Response View in Spring MVC

Currently I was looking for an example Spring MVC with JSON response view, most of the examples talks about Jackson API for JSON Response view. I couldn't understand why we need Jackson API for returning the response as JSON. Is there any other way to return JSON view in the response? And also I do not understand when we are using Jackson how view it is getting rendered as JSON Array values in response. Could somebody let me where we can get a clear idea on it.

Thanks in Advance.